C# Regex SSN and Date Validation

I'm looking for a sharp developer highly skilled in C#, specifically with regex, to create validation for a string. This string can be alpha and numeric like "123test123" or "test" but cannot be all numbers like "1209562783" or a date like "12/11/2000". The date must match any date format as well (MM/DD/YYYY and DD/MM/YYYY, including using a "-" or "/" as a separator). This code should be in a method that gets the string passed in, does the above validation and returns a bool value of true is it passes (meaning it is like "123test123" or "test") or false if it fails (matches all numbers or is a date)